Vehicle control device

ABSTRACT

In a vehicle control device in which a driver circuit which does not have a computing function and a computing device communicate with each other, there is provided a technology which can efficiently diagnose that both the driver circuit and the computing device normally communicate with each other by a simple technique. The vehicle control device according to the present invention transmits diagnosis data as a control command from a computing portion to the driver circuit, and the driver circuit sends inverted diagnosis data in which the diagnosis data is bit-inverted back to the computing portion. The computing portion diagnoses whether or not the communication between the computing portion and the driver circuit is normally performed, by using the diagnosis data and the inverted diagnosis data.

TECHNICAL FIELD

The present invention relates to a device which controls an operation ofa vehicle.

BACKGROUND ART

In the related art, an electronic control unit (ECU) which controls anoperation of a vehicle is provided with a driver integrated circuit (IC)which drives a vehicle load, and a microcomputer which controls thedrive IC, and drives and controls the vehicle load by transmitting aparallel signal from a microcomputer to the driver IC.

Meanwhile, in recent years, the level of functions required in the ECUand a demand for low costs have increased. Here, in order to reduce thecost by reducing the number of ports of the microcomputer, it has beenattempted to switch the parallel signal which is transmitted andreceived between the microcomputer and the driver IC to a serial signal.Communication in accordance with a micro-serial bus standard is anexample thereof.

When the microcomputer and the driver IC communicate with each other bythe serial signal, a plurality of control commands send and receiveserial data which is written in series. In this case, when anabnormality occurs in the serial communication between the microcomputerand the driver IC, a control command with respect to the entire vehicleload driven by the driver IC becomes abnormal. Therefore, when anabnormality occurs in the serial communication between the microcomputerand the driver IC, it is considered that immediate detection of theabnormality and a shift of the vehicle into a fail-safe mode arenecessary.

In the following PTL 1, a technology which relates to the detection ofan abnormality of an electronic control unit, and detects an abnormalityby echoing back (sending the data which is the same as the data receivedby a receiving side back to a transmitting side) control data, isdescribed.

In the following PTL 2, a technique which relates to detection of anabnormality of an electronic control unit, and in which a detectionsignal is transmitted from a comparator 23 to a transceiver 12, thecomparator 23 receives a comparison signal from the transceiver 12, andboth the signals are compared to each other and the result thereof isreported to a CPU 21, is described. In PTL 2, by using the technique, itis detected whether or not there is a location where a signal linebetween a microcomputer 11 and a transceiver 12 is disconnected.

In PTL 3, it is described that, in communication between a main computer1 a provided in an ECU1 and a sub-computer 1 b, the sub-computer 1 btransmits data which is read out when a reading mode is performed anddata in which all of the bits of the read-out data are inverted to themain computer 1 a, and the main computer 1 a compares the data to eachother. The main computer 1 a confirms whether or not the read-out datawhich is received from the sub-computer 1 b is normal, by theabove-described processing.

CITATION LIST Patent Literature

PTL 1: JP-A-2000-312151

PTL 2: JP-A-2011-229079

PTL 3: JP-A-4-170829

SUMMARY OF INVENTION Technical Problem

In the technology described in PTL 1, since the communication dataitself is echoed back, there is a possibility that the communicationdata cannot be detected when the communication data itself is abnormal.For example, if the echoed-back data is deviated to either of a bitvalue 0 or a bit value 1, even when an abnormality occurs at any of thebit positions, there is a possibility that the abnormality isincorrectly recognized as normal data.

In the technology described in PTL 2, additional costs for providing thecomparator 23 are necessary. In addition, since it is necessary to sendthe detection signal during the time when the microcomputer 11 and thetransceiver 12 do not communicate with each other, timing for performingthe detection is restricted.

In the technology described in PTL 3, since it is necessary to provide acomputing function together with the main computer 1 a and thesub-computer 1 b, costs tend to increase. In addition, since thesub-computer 1 b transmits both the read-out data and the bit-inverteddata thereof to the main computer 1 a, it is considered that a dataamount which communicates for performing diagnosis tends to increase.

In consideration of the above-described problems, an object of thepresent invention is to provide a technology which can efficientlydiagnose that both a driver circuit and a computing device can normallycommunicate with each other by a simple technique in a vehicle controldevice in which the driver circuit which does not have a computingfunction and the computing device communicate with each other.

Solution to Problem

A vehicle control device according to the present invention transmitsdiagnosis data as a control command from a computing portion to a drivercircuit, and the driver circuit sends inverted diagnosis data in whichthe diagnosis data is bit-inverted back to the computing portion. Thecomputing portion diagnoses whether or not communication between thecomputing portion and the driver circuit is normally performed, by usingthe diagnosis data and the inverted diagnosis data.

Advantageous Effects of Invention

According to the vehicle control device according to the presentinvention, since the driver circuit on the receiving side inverts thediagnosis data transmitted from the computing portion on thetransmitting side and sends the inverted data back to the computingportion, it is possible to reliably perform diagnosis. In addition,since the diagnosis data is transmitted as a control command from thecomputing portion to the driver circuit, it is possible to perform thediagnosis at arbitrary timing by the computing portion. Furthermore,since it is possible to easily perform the diagnosis even when thedriver circuit does not have a computing function, it is possible tosuppress the cost for implementing the computing function.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a configuration view of a vehicle control device 1000according to Embodiment 1.

FIG. 2 is a view illustrating a bit arrangement of a control frame.

FIG. 3 is a view illustrating a bit arrangement of a data frame.

FIG. 4 is a view schematically illustrating a configuration example of acommand map 220.

FIG. 5 is a view illustrating the bit arrangement of the data frame inupstream communication.

FIG. 6 is a view schematically illustrating a configuration example ofthe data frame in the upstream communication.

FIG. 7 is a view illustrating an example of timing when a microcomputer100 transmits the diagnosis data, and timing when a driver circuit 200transmits inverted diagnosis data back.

FIG. 8 is an example of a time chart of downstream communication andupstream communication.

DESCRIPTION OF EMBODIMENTS

<Embodiment 1>

FIG. 1 is a configuration view of a vehicle control device 1000according to Embodiment 1 of the present invention. The vehicle controldevice 1000 is an ECU which controls an operation of a functionalportion provided in a vehicle, and is provided with a microcomputer(computing portion) 100 and a driver circuit 200. Description of avehicle load which is driven by the driver circuit 200 will be omitted.

The microcomputer 100 is provided with software 110 and an MSB interface(I/F) 120. The software 110 is a software group, such as an applicationor a BIOS, which implements processing of control of the vehicleoperation. The MSB interface 120 is a communication interface whichperforms serial communication with the driver circuit 200. In Embodiment1, the serial communication in accordance with a microsecond busstandard is performed, but a communication method is not limitedthereto.

The MSB interface 120 is provided with a timer 121, a clock generator122, a transmission register 123, and a reception register 124. Theclock generator 122 generates a clock signal for synchronizing anoperation between the microcomputer 100 and the driver circuit 200, andoutputs the clock signal to the driver circuit 200 via one pair of clockwirings 320. The transmission register 123 is a register whichtemporarily accommodates the data transmitted from the MSB interface 120to the driver circuit 200, and is connected to the driver circuit 200via one pair of transmission wirings 330. The reception register 124 isa register which temporarily accommodates the data that the MSBinterface 120 receives from the driver circuit 200, and is connected tothe driver circuit 200 via one reception wiring 340.

The MSB interface 120 and the driver circuit 200 are further connectedto each other via enabling signal wiring 310. When issuing a controlcommand to the driver circuit 200, the MSB interface 120 transmits anenabling signal via the enabling signal wiring 310 at the same time whenthe control command is transmitted via the transmission wiring 330.

The driver circuit 200 is a driver IC which drives a vehicle load, andis configured to perform a function which is statically implemented on acircuit in advance. Therefore, the driver circuit 200 cannot execute aprogram, for example. The driver circuit 200 is provided with areception register 210, a command map 220, an output register 230, adriver 240, an execution result register 250, and a transmissionregister 260.

The reception register 210 is a register which temporarily accommodatesthe data received from the MSB interface 120 via the transmission wiring330. The command map 220 is a conversion table for converting a controlcommand received as a serial data into a control command which isparallel to each driver 240, and will be described in detail. The outputregister 230 is a register which temporarily accommodates the controlcommand which is converted by using the command map 220 and correspondsto each driver 240. The driver 240 is a circuit which drives eachvehicle load, and only a required number of drivers 240 are provided inaccordance with the type or the number of the vehicle loads driven bythe driver circuit 200. The execution result register 250 is a registerwhich receives operation data in which the obtained execution result iswritten from each driver 240 as a result of driving the vehicle load byeach driver 240, and temporarily accommodates the operation data. Thetransmission register 260 is a register which temporarily accommodatesdata transmitted to the MSB interface 120.

It is desirable that the transmission register 123 and the receptionregister 124 are configured to be separated from each other electricallyor logically so as to not cause bit interference. The reception register210 and the transmission register 260 are also similar to theconfiguration of the transmission register 123 and the receptionregister 124.

The command map 220 can be configured by using a circuit device whichrealizes the function thereof. It is technically possible to configurethe command map 220 by using the software implemented with equivalentfunctions and a processor which executes the software, but from theviewpoint of suppressing the implementation costs of the driver circuit200, it is desirable that the driver circuit is configured by only usingthe circuit device as described above.

<Embodiment 1: Communication from Microcomputer 100 to Driver Circuit200>

The microcomputer 100 transmits the control command to the drivercircuit 200 via the transmission wiring 330. There is also a case wherecommunication from the microcomputer 100 to the driver circuit 200 iscalled downstream communication. There are two types of frames in whichthe control command is written, such as a control frame and a dataframe. An example of the data frame will be described hereinafter.

FIG. 2 is a view illustrating a bit arrangement of the control frame.The control frame is a frame in which a control command in a narrowsense is written. The control frame includes one selection bitillustrating the type of the frame, 5 command bits (C0 to C4) in whichthe type of the control command is written, 11 data bits (D0 to D10) inwhich the contents of the control command are written, and two invalidbits. The MSB interface 120 activates the enabling signal at the sametime when transmitting the control frame to the driver circuit 200.

FIG. 3 is a view illustrating a bit arrangement of the data frame. Thedata frame is a frame for transmitting real data, such as numerical dataincluded in the control command. The data frame includes one selectionbit illustrating the type of the frame, 16 data bits (D0 to D15) inwhich contents of the data are written, and two invalid bits. The MSBinterface 120 activates the enabling signal at the same time whentransmitting the data frame to the driver circuit 200.

FIG. 4 is a view illustrating a configuration example of the command map220. Since the control command transmitted by the MSB interface 120 isin the serial data, the control command with respect to the plurality ofdrivers 240 is written in series. Here, the driver circuit 200 extractsthe control command with respect to each driver 240 that is written inthe serial data by using the command map 220, and accommodates thecontrol command in each output register 230. The output register 230accommodates the control command with respect to each driver 240 inparallel. In other words, the driver circuit 200 converts the controlcommand which is transmitted by the microcomputer 100 and written in theserial data, into the control command which is parallel to the pluralityof drivers 240, by using the command map 220.

When the data which is received from the microcomputer 100 and writtenin the control frame matches any bit pattern illustrated in FIG. 4, thedriver circuit 200 interprets that the bit row is the control commandwhich corresponds to the bit pattern.

In the example of the data illustrated in FIG. 4, 16 types of controlcommands are illustrated as examples, but the invention is not limitedthereto. In addition, the control command written as the first exampleis the diagnosis data which will be described later. In other words, thediagnosis data which will be described later is formally defined as onetype of control command.

<Embodiment 1: Communication from Driver Circuit 200 to Microcomputer100>

The driver circuit 200 has a function of self-diagnosing whether or notan abnormal state, such as an abnormal voltage generated by a circuitabnormality (for example, disconnection or a short circuit) in eachdriver 240, and accommodates the diagnosis result in the executionresult register 250 as an operation data. For example, when the abnormalvoltage is generated in the first driver 240, the driver circuit 200 hasa function of setting the first bit value of the execution resultregister 250 to be 1, or the like.

However, since the driver circuit 200 does not have a computingfunction, the meaning of each bit value accommodated in the executionresult register 250 cannot be interpreted. Here, the driver circuit 200converts the operation data accommodated in the execution resultregister 250 into the serial data, and transmits the data to themicrocomputer 100 via the transmission register 260 and the receptionwiring 340. The microcomputer 100 diagnoses the operation data receivedfrom the driver circuit 200 by the function implemented in the software110.

There is also a case where the communication from the driver circuit 200to the microcomputer 100 is called upstream communication. The drivercircuit 200 performs the downstream communication and the upstreamcommunication asynchronously. In other words, the driver circuit 200transmits the operation data in the execution result register 250, forexample, at a constant operation period, to the microcomputer 100regardless whether or not the control command is received from themicrocomputer 100.

FIG. 5 is a view illustrating the bit arrangement of the data frame inthe upstream communication. The data frame in the upstream communicationincludes 1 start bit, 4 bits of command field (C0 to C3), 2 bits ofaddress field (A0 to A1), 6 bits of data field (D0 to D5), 1 parity bit,and 2 stop bits. When the plurality of data frames are continuouslytransmitted, 1 inter-frame bit is provided between the data frames.Since the upstream communication performs asynchronously with thedownstream communication, the enabling signal is not necessary in theupstream communication.

FIG. 6 is view illustrating a configuration example of the data frame inthe upstream communication. The driver circuit 200 converts thediagnosis result regarding each driver 240 into the serial data inaccordance with a conversion rule as illustrated in FIG. 6, andaccommodates the result in the transmission register 260. The serialdata accommodated in the transmission register 260 is transmitted to themicrocomputer 100, for example, at a constant operation period. Sincethe conversion rule illustrated in FIG. 6 is conversion which is reverseto processing of converting the serial data into the parallel data inthe downstream communication, it is possible to implement the conversionrule on the command map 220.

<Embodiment 1: Diagnosis Data>

The driver circuit 200 transmits the operation data illustrating thepresence or the absence of the abnormality in each driver 240 to themicrocomputer 100. The abnormality diagnosis by the operation data ismore likely to be diagnosis of an abnormality of the vehicle load, andis unlikely to diagnose an abnormality occurred in the driver circuit200 itself.

Meanwhile, in the reception register 210 provided in the driver circuit200, when an abnormality, such as bit-fixing (bit at a certain locationis fixed), occurs, there is a possibility that the control command isnot correctly transferred to the driver 240, and the vehicle operationis in a dangerous state. Similarly, when the abnormality occurs in thetransmission register 260, the microcomputer 100 cannot correctlydiagnose the operation of the driver 240. Similar failure can begenerated even when the abnormality occurs in the transmission wiring330 and the reception wiring 340.

There is a possibility that the driver circuit 200 itself canself-diagnose the above-described abnormality of the driver circuit 200as the driver circuit 200 has the computing function and checks the dataon each register or the data on each wiring, for example, by paritychecking or the like. However, when the computing function is includedin the driver circuit 200, the implementation costs of the drivercircuit 200 increase. In addition, when the driver 240 is implemented inthe driver circuit 200, there is a tendency that the driver 240 islikely to generate heat, and a cause of the generation of heat is addedto when the computing function is further added. For this reason,implementing the driver 240 in the driver circuit 200 is not preferablefrom the viewpoint of a countermeasure against heat.

Here, in Embodiment 1, the microcomputer 100 transmits the diagnosisdata for diagnosing whether or not the communication with the drivercircuit 200 is normally performed to the driver circuit 200, and sendsthe bit-inverted data in which the diagnosis data is bit-inverted backto the microcomputer 100. The microcomputer 100 acquires a logical sumof the diagnosis data and the inverted diagnosis data, and if the bit ofall of the results is 1, it is possible to confirm that thecommunication with the driver circuit 200 is normally performed.

The bit arrangement of the diagnosis data is arbitrary. For example,when “1100” is transmitted as the diagnosis data, the driver circuit 200sends “0011” which is the inverted diagnosis data inverted from thediagnosis data back to microcomputer 100. The microcomputer 100 acquiresthe logical sum of “1100” and “0011”, and if the bit of all of theresults is 1 (1100+0011=1111), it is ascertained that the communicationwith the driver circuit 200 is normally performed. In other words, it ispossible to confirm that the abnormality does not occur in any of thereception register 210, the transmission register 260, the transmissionwiring 330, and the reception wiring 340.

FIG. 7 is a view illustrating an example of timing when themicrocomputer 100 transmits the diagnosis data, and timing when thedriver circuit 200 sends the inverted diagnosis data back. Varioustimings when the microcomputer 100 transmits the diagnosis data to thedriver circuit 200 can be considered. In Embodiment 1, the diagnosisdata is defined as one type of the control command from themicrocomputer 100 to the driver circuit 200, and at the timing when themicrocomputer 100 transmits the control command to the driver circuit200, the diagnosis data can always be transmitted.

In the example illustrated in FIG. 7, the microcomputer 100 transmitsthe diagnosis data to the driver circuit 200 within an arbitraryexecution period. The diagnosis data is defined as a control command“RD_DATA” illustrated as the first example of FIG. 4. The driver circuit200 can determine whether or not the diagnosis data arrives by using thecommand map 220. When the control command RD_DATA arrives, the drivercircuit 200 accommodates the inverted diagnosis data in which all of thebits of RA_DATA are inverted in the execution result register 250.

In the execution period for performing the upstream communication, thedriver circuit 200 converts the operation data to the serial data inaccordance with a conversion rule illustrated in FIG. 6. Furthermore,when the inverted diagnosis data is accommodated in the execution resultregister 250 in the previous execution period, the inverted diagnosisdata is added to an appropriate position (for example, an end position)in the serial data.

In a case where the diagnosis data is transmitted to the driver circuit200, then, when the upstream communication is received, themicrocomputer 100 receives the inverted diagnosis data together with theoperation data. The microcomputer 100 performs diagnosis in accordancewith the above-described diagnosis rule.

FIG. 8 is an example of a time chart of the downstream communication andthe upstream communication. Hereinafter, the example of the time chartof FIG. 8 will be described.

Since the microcomputer 100 and the driver circuit 200 perform serialcommunication, it is necessary to set a control period of the downstreamcommunication combining with the required shortest communication period.In other words, it is necessary to satisfy the shortest control periodamong the control periods required for each vehicle load. Furthermore,when two-consecutive collating (the same data is transmitted two timesin a row, and the data is considered as normal if the same data istransmitted two times) is used for confirming probability of controlcommand, it is necessary to transmit the control command at a period of½ of the shortest period.

In the example illustrated in FIG. 8, it is assumed that 3 types ofloads, such as a relay load, an injector load, and an ignition loadexist, and the control period required for the ignition load is theshortest period which is 3.2 μs. For this reason, it is necessary forthe microcomputer 100 to transmit the control command to the drivercircuit 200 at a period of 1.6 μs. A specific communication period maybe appropriately determined in accordance with a load specification orrequired accuracy. As other types of load, for example, a solenoidcircuit or a heater circuit are considered.

In addition, in the arbitrary communication period, the microcomputer100 transmits the above-described diagnosis data (RD_DATA) to the drivercircuit 200. Since the diagnosis data is defined as one control command,and it is possible to transmit the diagnosis data at arbitrary timing ifthere is no restriction, such as an order of the control command.

The driver circuit 200 performs the upstream communicationasynchronously with the downstream communication, and transmits theoperation data of each driver 240 to the microcomputer 100. When thediagnosis data is received at the previous upstream communicationperiod, the driver circuit adds the inverted diagnosis data(INV_RD_DATA) in which the diagnosis data is bit-inverted to anappropriate location (in the example illustrated in FIG. 8, the endlocation) in the upstream communication.

When the diagnosis data is transmitted in the following downstreamcommunication period, the microcomputer 100 transmits the data (whichbecomes equivalent to INV_RD_DATA) in which the diagnosis data of theprevious period is bit-inverted to the driver circuit 200 as newdiagnosis data. After this, similarly, the bit is inverted every timewhen the diagnosis data is transmitted. This is because all of the bitpositions are diagnosed uniformly. Specific reasons thereof will bedescribed in Embodiment 2.

The communication period of the upstream communication may be arbitrary(for example, a period of 10 ms), but since a computing load increaseswhen a communication frequency increases, it is desirable to suppressthe communication period to be as short as possible. For example, thecommunication period may be a communication speed which is necessarywhen performing the vehicle diagnosis, such as an OBD2 (on boarddiagnosis 2) on the microcomputer 100 side.

As timing for performing diagnosis processing illustrated in the exampleof FIG. 8, timing before the vehicle is started is desired.Specifically, it is desirable to perform the diagnosis processing attiming from the release of resetting of the vehicle control device 1000to the start of the engine.

<Embodiment 1: Conclusion>

As described above, in the vehicle control device 1000 according toEmbodiment 1, the microcomputer 100 transmits the diagnosis data to thedriver circuit 200 as one control command, and the driver circuit 200sends the inverted diagnosis data in which the diagnosis data isbit-inverted back to the microcomputer 100. Accordingly, at arbitrarytiming of transmitting the control command, the microcomputer 100 candiagnose whether or not the communication with the driver circuit 200 isnormally performed.

In addition, in the vehicle control device 1000 according to Embodiment1, the microcomputer 100 performs the above-described diagnosisaccording to whether or not all of the bits of the logical sum of thediagnosis data and the inverted diagnosis data is 1. Since the diagnosisrule is the same regardless of the bit arrangement of the diagnosisdata, it is possible to simplify the diagnosis processing on themicrocomputer 100 side (it is not necessary to compare each bit indetail). In addition, since the driver circuit 200 may only invert thebit, it is possible to implement the above-described processing withoutusing the computing function, for example, by a circuit (NOT circuit)which increases or decreases the voltage value showing the bit value.

In addition, in the vehicle control device 1000 according to Embodiment1, the driver circuit 200 performs the upstream communicationasynchronously with the downstream communication. Accordingly, since itis not necessary for the microcomputer 100 to wait for the result whichtransmits the diagnosis data, it is possible to further freely set thetiming of transmitting the diagnosis data.

In addition, in the vehicle control device 1000 according to Embodiment1, the driver circuit 200 makes the inverted diagnosis data in serialand transmits the inverted diagnosis data to the microcomputer 100together with the operation data in which the self-diagnosis result ofeach driver 240 is written. Accordingly, since it is necessary toseparately provide the communication period for transmitting theinverted diagnosis data, it is possible to alleviate the communicationload.

In addition, in the vehicle control device 1000 according to Embodiment1, the microcomputer 100 and the driver circuit 200 are connected toeach other by a total of 6 wirings, such as 1 enabling wiring 310, 1pair of clock wirings 320, 1 pair of transmission wirings 330, and 1reception wiring 340, and performs the serial communication inaccordance with an MSB standard. Accordingly, it is possible to suppressthe number of terminals and wirings of each of the microcomputer 100 andthe driver circuit 200 to be small.

<Embodiment 2>

In Embodiment 1, it is described that the diagnosis data transmitted bythe microcomputer 100 may be arbitrary. However, in order to perform thediagnosis more efficiently, there is room for consideration of the bitarrangement of the diagnosis data. Here, in Embodiment 2 of the presentinvention, the bit arrangement of the diagnosis data which can performthe diagnosis more efficiently will be reviewed. The configuration ofthe vehicle control device 1000 is similar to that of Embodiment 1.

When the abnormality occurs in each register or wiring, there is apossibility that the bit value at a certain position is fixed to be thesame value (bit-fixing). In order to detect the bit-fixing during acommunication period as short as possible, it is desirable that themicrocomputer 100 inverts all of the bits every time when themicrocomputer 100 transmits the diagnosis data, and all of the bitswithin the two-communication period have both the bit value 0 and thebit value 1. This is similar to both the transmission register 123 andthe reception register 124, and in addition, similar to both thereception register 210 and the transmission register 260 in the drivercircuit 200.

In addition, there is a possibility that each register causes a shortcircuit due to a foreign substance, such as an adjacent bit, and anabnormality in which the bits always become the same value (bitshort-circuiting) occurs. In order to avoid bit short-circuiting, it isdesirable that the diagnosis data alternately have the bit value 0 andthe bit value 1.

In consideration of the description above, it is desirable that the dataalternately have the bit value 0 and the bit value 1 as the diagnosisdata transmitted by the microcomputer 100, and the bit value is invertedevery time when the diagnosis data is transmitted. In the example ofRD_DATA illustrated on the first row of FIG. 4, based on the review,both the bit arrangement which starts from the bit value 0 and the bitarrangement which starts from the bit value 1, are defined as theRD_DATA.

<Embodiment 2: Conclusion>

As described above, the vehicle control device 1000 according toEmbodiment 2 uses the bit arrangement which alternately have the bitvalue 0 and the bit value 1 as the diagnosis data. Accordingly, it ispossible to detect the bit-fixing within the two-communication period,and to avoid wrong diagnosis due to the bit short-circuiting.

<Embodiment 3>

In the above-described Embodiments 1 to 2, when the abnormal bit isdetected at any position of the diagnosis data, the microcomputer 100can detect that the register address which corresponds to the bitposition is abnormal. However, this abnormality is an abnormality whichis detected by issuing the diagnosis data, and is not based on theoperation data obtained from the driver 240. In other words, thisabnormality does not show the vehicle load or an abnormality of thedriver 240. At this time, as an operation which is performed by themicrocomputer 100, for example, the following operations can beconsidered.

(Operation Example 1 when Abnormality is Detected)

The microcomputer 100 issues the control command of an indication tostop the vehicle load which corresponds to the bit position at which theabnormality is detected or the driver 240. However, since there is apossibility that the control command is not normally transferred to thedriver 240 when the register is broken, it is necessary to transfer thecontrol command to the driver 240, for example, via separatecommunication wiring.

(Operation Example 2 when Abnormality is Detected)

When the abnormality is detected at any of the bit positions of thediagnosis data, the microcomputer 100 switches the vehicle operation toa safety side, and the operation of the driver circuit 200 is stopped.Specifically, the enabling signal may be deactivated, and an operationstop command may be issued as the control command.

(Operation Example 3 when Abnormality is Detected)

The microcomputer 100 outputs the signal which shows the bit position atwhich the abnormality is detected or the contents equivalent thereto,for example, to the control device on a higher level.

<Embodiment 4>

The present invention is not limited to the above-described embodiments,and includes various modification examples. The above-describedembodiments are described in detail to make the present invention easyto understand, but the invention is not necessarily limited to all ofthe configurations described above. In addition, it is possible toswitch a part of a configuration of a certain embodiment to aconfiguration of another embodiment. In addition, it is possible to adda configuration of another embodiment to a configuration of a certainembodiment. In addition, it is possible to add, remove, and switchanother configuration with respect to a part of a configuration of eachembodiment.

In embodiments 1 to 3, as long as the restriction conditions, such as adevice cost, is allowed, the driver circuit 200 can be configured byusing a circuit device (an FPGA or the like) which is programmable bydynamically changing the circuit configuration, and the driver circuit200 can be configured by only performing the function implemented on thecircuit board in advance as described in Embodiment 1, and by using thecircuit device which cannot dynamically change the circuitconfiguration. Otherwise, a minimum computing function which is notsufficient to realize the function given to the driver circuit 200 maybe imparted to the driver circuit 200.

In Examples 1 to 3, it is described that the driver circuit 200transmits the diagnosis data as the bit-inverted diagnosis data, but itis not necessary to invert and simultaneously transmit all of the bitsof the diagnosis data, and only a part of the bits may be repeatedlyinverted and transmitted. The microcomputer 100 diagnoses the entiretyof the diagnosis data by repeating the diagnosis sequentially by usingthe bit-inverted data which is received from the driver circuit 200.

When a part of the bits of the diagnosis data is inverted, for example,switching of the command map 220 is indicated by the downstreamcommunication from the microcomputer 100 to the driver circuit 200, andall of the bits may be diagnosed by performing the diagnose in order. Inthis case, on the command map 220, the command to make the diagnose databit-inverted by a technique, such as a bit shift, is written, and thedriver circuit 200 may perform the bit inversion by using the command.However, since the implementation costs or a diagnosis processing loadof the driver circuit 200 increases, it is desirable to invert all ofthe bits at a time.

REFERENCE SIGNS LIST

-   -   100: MICROCOMPUTER    -   110: SOFTWARE    -   120: MSB INTERFACE    -   121: TIMER    -   122: CLOCK GENERATOR    -   123: TRANSMISSION REGISTER    -   124: RECEPTION REGISTER    -   200: DRIVER CIRCUIT    -   210: RECEPTION REGISTER    -   220: COMMAND MAP    -   230: OUTPUT REGISTER    -   240: DRIVER    -   250: EXECUTION RESULT REGISTER    -   260: TRANSMISSION REGISTER    -   310: ENABLING SIGNAL WIRING    -   320: CLOCK WIRING    -   330: TRANSMISSION WIRING    -   340: RECEPTION WIRING    -   1000: VEHICLE CONTROL DEVICE

The invention claimed is:
 1. A vehicle control device, comprising: acomputing circuit; and a driver circuit which drives one or more of aplurality of functional portions of a vehicle in accordance with aserial control command received from the computing circuit, wherein thedriver circuit includes a plurality of drivers that are configured toperform functions which are statically implemented on the circuit inadvance; a transmission wiring, wherein the transmission wiringpropagates a signal transmitted from the computing circuit to the drivercircuit; and a reception wiring, wherein the reception wiring propagatesa signal transmitted from the driver circuit to the computing circuit,wherein the computing circuit: transmits diagnosis data to the drivercircuit as the control command, asynchronously receives, from the drivercircuit using the reception wiring, inverted diagnosis data, wherein theinverted diagnosis data includes at least a part of the diagnosis datareceived by the driver circuit that is bit-inverted, diagnoses whetheror not the computing circuit and the driver circuit are communicatingnormally based on the diagnosis data and the inverted diagnosis dataperforms a bit-inversion of the diagnosis every time the diagnosis datais transmitted to the driver circuit.
 2. The vehicle control deviceaccording to claim 1, wherein the computing circuit further: transmitsthe diagnosis data to the driver circuit at any execution period ofoutputting the control command to the driver circuit, and wherein thedriver circuit generates the inverted diagnosis data by bit-invertingthe diagnosis data when the diagnosis data is received from thecomputing circuit in an execution period before transmitting theoperation data to the computing circuit.
 3. The vehicle control deviceaccording to claim 1, wherein the driver circuit further includes areception register that stores data received from the computing circuitvia the transmission wiring, and a transmission register that storesdata transmitted to the computing circuit via the reception wiring, andwherein the reception register and the transmission register areconfigured to be separated so as to not cause bit interference.
 4. Thevehicle control device according to claim 3, wherein the computingcircuit diagnoses a location where an abnormality occurs in thereception register or the transmission register, and outputs a signalwhich shows a result thereof, by specifying the location in which a bitabnormality occurs in the diagnosis data or the inverted data, and byusing the diagnosis data and the inverted diagnosis data.
 5. The vehiclecontrol device according to claim 4, wherein the computing circuitoutputs the control command which indicates to stop the driver circuitto the driver circuit when a location where a bit abnormality occursexists in the diagnosis data or the inverted data, and wherein thedriver circuit stops an operation of driving one or more of theplurality of functional portions in accordance with the control commandreceived from the computing circuit.
 6. The vehicle control deviceaccording to claim 1, wherein the computing circuit transmits data inwhich a bit value 0 and a bit value 1 are alternately disposed, to thedriver circuit as the diagnosis data.
 7. The vehicle control deviceaccording to claim 1, wherein the computing circuit further: transmitsthe control command to the driver circuit, wherein the driver circuit:receives the control command from the computing circuit, converts thecontrol command into a plurality of parallel control commands based on areception command map which defines a corresponding relationship betweenbit data written in the control command and the plurality of drivers,and concurrently issues the plurality of parallel control commands tothe plurality of drivers as serial data.
 8. The vehicle control deviceaccording to claim 7, wherein the computing circuit and the drivercircuit communicate with each other in accordance with a microsecond busstandard.
 9. The vehicle control device according to claim 1, whereinthe driver circuit further: transmits operation data that indicates anoperation results of the plurality of functional portions to thecomputing circuit in one serial data transmission.
 10. The vehiclecontrol device according to claim 1, wherein the transmission wiringincludes one pair of transmission wirings; wherein the reception wiringincludes one pair of reception wirings; the vehicle control devicefurther comprising: one pair of clock wirings which transmit a clocksignal from the computing circuit to the driver circuit; and onevalidating signal wiring which transmits a validating signal thatindicates validation of communication via the transmission wiring andthe reception wiring, from the computing circuit to the driver circuit.11. The vehicle control device according to claim 1, wherein the drivercircuit drives at least any one of a solenoid circuit provided in thevehicle, a relay circuit provided in the vehicle, an injector circuitprovided in the vehicle, an ignition circuit provided in the vehicle,and a heater circuit provided in the vehicle, as one or more of theplurality of functional portions.